Some computers, such as notebook computers, have an external power adapter that converts alternating current (AC) voltage to direct current (DC) voltage for consumption by the computer. The DC voltage provided to the computer can be used to operate the logic circuits in the computer as well as to charge a battery. Different voltages may be required for battery charging as opposed to operating the computer's logic circuits. Additionally, a computer may be able to draw more current than the power adapter is rated to provide.